Lung diseased patients often need supplemental oxygen to improve their comfort and/or quality of life. Stationary sources of oxygen are available, e.g., oxygen lines in hospitals or other facilities, that may provide oxygen to patients. To allow some mobility, cylinders of pure and/or concentrated oxygen can be provided that a patient may carry or otherwise take with them, e.g., on pull-along carts. Such cylinders, however, have limited volume and are large and heavy, limiting the patient's mobility.
Portable devices have been suggested that concentrate oxygen from ambient air to provide supplemental oxygen. For example, pressure swing adsorption (“PSA”) apparatus are known that separate nitrogen from ambient air, delivering a stream of concentrated oxygen that may be stored in a tank or delivered directly to patients. For example, U.S. Pat. Nos. 5,531,807 6,520,176, and 6,764,534 disclose portable PSA oxygen concentrators.
Accordingly, apparatus and methods for providing oxygen would be useful.